Providing sustainable water supply and sanitation (WSS) services in developing countries remains an immense, and increasingly urgent, challenge. Chapter two sets out how the sector is currently funded and why business as usual is insufficient for meeting WSS-related goals, covering the size of the investment gap, and the challenges presented by the status quo. Chapter three proposes a financing framework toward more effective use of existing funds to enable the mobilization of new sources of finance, and explains the benefits and costs of commercial finance. Chapters four to six detail the three components of the financing framework, providing practical advice and global experiences that demonstrate how countries can begin to make progress. Chapter seven summarizes how stakeholders can bring the three components together to mobilize commercial finance, and provides the main conclusions and recommendations of the report.